If you don't understand that gravity is a work of God, you don't really understand about gravity.
There is no evidence for God!!!
gravity does what it does without having any gravity theory involved. People who are affected by gravity, and want to call the affect "gravity," don't need to understand gravity theory to know that it's gravity.
True. But a benefit of having the scientific explanation is that science advances. If we just relied on the stuff that we can physically witness, without trying to understand what it is and how it works, we'd still be living in caves.
Engineers using physics doesn't have anything to do with engineering. We all use physics all the time for everything that we do. Or do you think that if we aren't engineers, or that engineers themselves, suddenly stop using the physics of the universe? Maybe at death. Is that what you are talking about?
Not sure what you're suggesting. Engineers use physics (and the laws of physics), yes.